Nacelle structures for jet engines of an aircraft provide a housing within which the jet engine is supported. The nacelle structure typically includes a thrust reverser that can provide assistance in slowing the aircraft by redirecting the engine thrust. The thrust reverser includes a panel (referred to as a translating sleeve) of the nacelle that is translated between a stowed position, for normal operation during flight, and a deployed position, for redirecting the engine thrust, such as during landing of the aircraft. The thrust reverser panel slides along a track beam to move between the stowed position and the deployed position.
Thrust reverser track beams support the thrust reverser panel during translation and join the thrust reverser panels and an engine strut or pylon for under-wing carriage of the nacelle. Other installations of jet engines may enclose the engine within a fuselage portion of the aircraft, in which case the beams join the thrust reverser panels to the aircraft fuselage.
Thrust reverser track beams have conventionally been machined from solid ingots of metal, such as aluminum. As engine diameters and bypass ratios have increased, the engine weight has increased commensurately. Such engines use larger and stronger beams. More recently, composite track beams have been proposed, in which the generally closed-form beam is constructed from a composite material, such as graphite fiber layers impregnated with a resin material to form a graphite composite structure. Existing lugs for track beams are coupled to the track beam via co-curing, adhesive bonding, or fastening with the lug attached on the same side of the track beam as the component to which the lug is attaching. The design of lugs incorporated into composite beams often rely on interlaminar properties of composite materials to support high structural loads. However, the interlaminar properties are generally weaker than the in-plane properties of the composite materials.